Rapid advances in electronics and communication technologies, driven by immense customer demand, have resulted in the widespread adoption of mobile communication devices. Many of these devices, e.g., smartphones, have sophisticated processing capability and rely on clocks of different frequencies to perform different processing tasks, e.g., decoding and playback of encoded audio files. These devices may rely on portable power sources that are periodically charged. The ease and speed of the charging process may contribute to the commercial success of the device.